Abstract
BACKGROUND: Skeletal muscle dysfunction (SMD) is one of the most prominent extrapulmonary effects of chronic obstructive pulmonary disease (COPD). Myostatin negatively regulates the growth of skeletal muscle. We confirmed that myostatin expression is significantly increased in the quadriceps femoris muscle tissue of rats with COPD and is involved in the development of SMD in COPD, but the mechanism by which this occurs has yet to be uncovered. Dynamin-related protein 1 (Drp-1) has been shown to promote apoptosis and affect cellular energy metabolism by mediating enhanced mitochondrial division. Preliminary findings from our group illustrated that mitochondrial division and Drp-1 expression were increased in COPD quadriceps femoris cells. However, it is not yet clear whether mitochondrial dynamics are affected by myostatin in COPD quadriceps myocytes. METHODS: The study sought to explore the effects and potential mechanisms of myostatin on skeletal muscle atrophy, mitochondrial dynamics, apoptosis, and the links between related processes in COPD. RESULTS: Our findings showed that cigarette smoke exposure stimulated an increase in myostatin, increased superoxide production, decreased mitochondrial membrane potential, significantly promoted Drp-1-mediated mitochondrial fission, and promoted apoptosis. CONCLUSIONS: In summary, our study demonstrated that cigarette smoke led to increased Drp-1 expression and enhanced mitochondrial division by upregulating myostatin, which in turn promoted apoptosis and affected cellular energy metabolism, leading to the development of SMD in COPD. This study extends understandings of skeletal muscle function in COPD and provides a basis for the use of myostatin and Drp-1 as novel therapeutic targets for SMD in COPD.